Method and system for measuring coating thickness
US11085755B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 26, 2018 |
| Grant date | Aug 10, 2021 |
| Priority date | — |
| Expiry date | Jan 26, 2038 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N33/32
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for determining the thickness of a plurality of coating layers, the method comprising: performing a calibration analysis on calibration data to determine initial values and search limits of optical parameters of said plurality of coating layers, irradiating the said plurality of layers with a pulse of THz radiation, said pulse comprising a plurality of frequencies in the range from 0.01 THz to 10 THz; detecting the reflected radiation to produce a sample response said sample response being derived from the reflected radiation; producing a synthesised waveform using the optical parameters and predetermined initial thicknesses of said layers; and varying said thicknesses and varying said optical parameters within the said search limits to minimise the error measured between the sample response and the synthesised waveform; and outputting the thicknesses of the layers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.